This invention relates generally to a two-way communication system of the type which may be utilized with a protective helmet such as the helmet worn by the military, construction workers, factory workers, fire fighters and motorcyclists. More particularly, the present invention relates to an improved two-way communication system which approximates two-way real time communication.
Two-way communication systems are, of course, well known as exemplified by the U.S. Pat. No. 3,366,880 to Driver, U.S. Pat. No. 3,968,435 to Stover and U.S. Pat. No. 3,283,074 to Csicsatka. Of these three prior patents, the Stover patent, of course, relates to a two-way communication system for use with a helmet.
There are various problems with the two-way communication systems of the prior art. One of the problems has been the need to manually switch the system between a transmit mode and a receive mode. This has been overcome, in part, by voice controlled systems such as that disclosed in the Csicsatka patent referred to above.
However, prior to the present invention, even voice-controlled communication systems suffer from severe limitations.
For example, when such systems are being utilized, the person initially receiving a communication must wait an inordinate amount of time before responding to the person initially speaking. This is because the systems heretofore developed include a substantial delay in switching from the transmit mode to the receive mode. As a consequence of the delay, the person initially listening to the conversion must wait, before commencing a response, otherwise the initial portion of the return communication is not received. This results in a very stilted pattern of communications between users of these systems.
As a practical example of this delay, a person initially listening cannot interrupt, even at the end of a sentence, to warn the person speaking of an imminent danger.
We have discovered that it is possible to approach two-way real time communication, simulating actual speech patterns, by providing a system which substantially immediately switches into the receive mode when the user of the system is not speaking. This switching occurs during time intervals between words, during pauses in speech and at the end of sentences and the like to thus permit immediate responses over the communication system.
Another shortcoming of the prior systems is that exemplified by the aforementioned Stover Patent which is designed for use in the near field. Systems which are designed to operate in the near field are dependent on the spatial relationship between users of the system, as hereinafter explained, and thus provide a significant limitation on the distance over which these systems may be utilized.
We have determined that such a limitation is not feasible for a two-way communication system and hence our system is predominantly designed for use in the far field region.
Thus the present invention overcomes the heretofore described limitations of the prior art by providing a two-way voice controlled communication system which approximates two-way real time communications and which is designed primarily for use in the far field independent of the spatial relationship between users of the system.